Umbrella with two-piece, pivotable ribs to prevent wind damage

ABSTRACT

An umbrella includes a mast, a hub supported by the mast, a plurality of ribs extending radially outward from the hub, and a canopy supported by the ribs. Each of the ribs comprises an inner rib section having an inner end mounted to the hub. An outer rib section is pivotably mounted to the outer end of the inner rib section. A stop means engageable by one of the inner and outer rib sections limits pivotable movement of the outer rib section with respect to the inner rib section such that when the stop means is engaged, the inner rib section and the outer rib section are substantially longitudinally aligned. When wind pressure underneath the umbrella reaches a predetermined level, the outer rib sections are pivoted upward, thereby relieving the wind pressure underneath the canopy rather than

TECHNICAL FIELD

[0001] This invention relates in general to large, outdoor umbrellas used to provide shade or other protection from the elements, and relates more specifically to an umbrella having two-piece, pivotable ribs to prevent wind damage.

BACKGROUND OF THE INVENTION

[0002] A major problem with large, outdoor umbrellas concerns the problem of wind getting underneath the canopy. Particularly with the ribs of the umbrella that support the canopy being angled upward toward the center of the umbrella, where there is no place for the air to escape, pressure underneath the umbrella can reach sufficient levels that the ribs of the umbrella can bend or break.

[0003] Some umbrellas attempt to address this problem by providing a dual-canopy arrangement. A hole is formed in the central portion of the main canopy, through which air can escape. This hole is covered by a second canopy that protects the opening from the elements. However, even in the case of dual-canopy umbrellas, wind pressure can build up faster than it can escape through the opening and still reach sufficient levels to cause damage to the umbrella ribs.

SUMMARY OF THE INVENTION

[0004] Stated generally, the present invention comprises an umbrella including a mast, a hub supported by the mast, a plurality of ribs extending radially outward from the hub, and a canopy supported by the ribs. Each of the ribs comprises an inner rib section having an inner end mounted to the hub. An outer rib section is pivotably mounted to the outer end of the inner rib section. A stop means engageable by one of the inner and outer rib sections limits pivotable movement of the outer rib section with respect to the inner rib section such that when the stop means is engaged, the inner rib section and the outer rib section are substantially longitudinally aligned. When wind pressure underneath the umbrella reaches a predetermined level, the outer rib sections are pivoted upward, thereby relieving the wind pressure underneath the canopy rather than breaking or bending the ribs.

[0005] Thus it is an object of the present invention to provide an improved umbrella of the large, outdoor type used to provide shade or other protection from the elements.

[0006] It is another object of the present invention to provide an improved outdoor umbrella that will provide a means for relieving the buildup of wind pressure underneath the canopy of the umbrella.

[0007] It is still another object of the present invention to provide an improved outdoor umbrella that will resist breakage and bending of ribs in response to buildup of wind pressure underneath the canopy of the umbrella.

[0008] Other objects, features, and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is a side view of an umbrella according to the present invention.

[0010]FIG. 2 is a top view of the umbrella of FIG. 1.

[0011]FIG. 3 is a cutaway view as seen along line 3-3 of FIG. 2.

[0012]FIG. 4 is a top view of the umbrella of FIG. 1 with the canopy illustrated in phantom lines to show the umbrella frame.

[0013]FIG. 5 is a perspective view of a housing of a rib hinge of the umbrella of FIG. 1.

[0014]FIG. 6 is a perspective view showing the housing of FIG. 5 with an outer rib section being inserted into its rearward end.

[0015]FIG. 7 is a perspective view of the assembled housing and outer rib section of FIG. 6 showing an inner rib section being inserted into the forward end of the housing.

[0016]FIG. 8 is a perspective view of the assembled housing, outer rib section, and inner rib section of FIG. 7.

[0017]FIG. 9 is a perspective view of the assembly of FIG. 8 showing the placement of a hole through the housing and inner rib section.

[0018]FIG. 10 is a perspective view of the assembly of FIG. 9 showing a pivot pin positioned within the hole so as to pivotably mount the inner rib section to the housing.

[0019]FIG. 11 is a side view of a first embodiment of a hinged rib assembly in its normal configuration.

[0020]FIG. 12 is a side view of the hinged rib assembly of FIG. 11 in a collapsed configuration.

[0021]FIG. 13 is a side view of a second embodiment of a hinged rib assembly in its normal configuration.

[0022]FIG. 14 is a side view of the hinged rib assembly of FIG. 13 in a collapsed configuration.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENT

[0023] Referring now to the drawings, in which like numerals indicate like elements throughout the several views, FIGS. 1-4 show an umbrella 10 according to an embodiment of the present invention. The umbrella 10 includes an umbrella canopy 12 fashioned from fabric panels. The canopy 12 is supported at one side by a mast 14 on a framework comprising a plurality of ribs 16 (FIGS. 3, 4) in the conventional manner, as explained below in greater detail. The umbrella canopy 12 is selectively foldable from the open position shown in FIGS. 1-4 to a closed position wherein the canopy lies alongside and generally parallel to the mast assembly 14. When opened, the canopy 12 is selectably adjustable between a horizontal or untilted attitude and various degrees of tilt. These features are disclosed in detail in my U.S. Pat. No. 5,937,882, which is incorporated herein by reference.

[0024] The mast assembly 14 is maintained in an upright position by a base 18. The base 18 in the preferred embodiment comprises a hollow pipe section 19 open at its upper end to telescopically receive the mast assembly 14 extending in a generally vertical direction up from the base. The base 18 preferably includes a securing element such as the setscrew 22 or the like to engage and retain the mast assembly 14 within the base, thereby preventing the mast assembly from pivoting on the base in response to breezes or other forces acting on the umbrella canopy 12. The base 18 can be mounted to the substructure by bolts or can be counterweighted to offset the weight of the umbrella canopy.

[0025] The mast assembly 14 includes an elongate tubular mast 20 having a lower portion configured for a telescopic fit within the upper end of the base 18, as previously mentioned. A housing 37 which is affixed to the mast 20 accommodates a winding mechanism 38 including a hub located within the hollow interior of the mast. The mast 20 extends above the housing 37 to an upper end closed by a cap 39. The mast 20 from its capped upper end to its lower end preferably is a single length of pipe or other tubular stock, with the winding hub accommodated in a transverse opening formed in the mast within the housing 37.

[0026] A collar 43 is received for sliding movement along the upper portion of the mast 20 extending between the housing 37 and the cap 39. A U-shaped notch may be formed in the upper edge of the collar 43 to accommodate a stop pin inserted through a selected one of the several openings 49 through the mast at intervals along the upper portion of the mast 20. The stop pin preferably is attached to the collar 43 by a security chain. With the stop pin in place in a selected hole 49, the stop pin engages the notch and prevents further upward movement of the collar 43 along the mast 20. Alternatively, a hole through the collar 43 can substitute for the notch so as to fix the collar to the mast 20 without movement in either direction along the mast.

[0027] The umbrella canopy 12 includes an arm 54 connected at one end to an upper hub 55 in the central portion of the umbrella canopy and radially extending to a distal end pivotably attached to one side of the collar 43. The ribs 16 that support the umbrella canopy 12 extend radially outward from the upper hub 55. A brace 56 pivotably attaches at one end to the cap 39 at the top of the mast, and extends to the other end 57 pivotably connected to the arm 54 between the center region 55 of the umbrella canopy and the distal end of the arm. The arm 54 thus supports the umbrella canopy 12 on the mast assembly 14, and also functions as one rib of the canopy assembly. The arm 54 preferably is located immediately below the adjacent fabric panels 15 of the canopy, with the connection 57 for the brace 56 extending upwardly through a suitable opening in the canopy 12.

[0028] A tension line 60 is wound on the winder hub inside the mast 20 and extends upwardly within the mast to a stationary pulley mounted adjacent the upper end of the mast. The line 60 passes over the pulley and extends downwardly outside the mast to pass over a second pulley carried by the collar 43 adjacent the distal end of the umbrella arm 54. The line then extends from the second pulley inside the hollow arm 54 to pass over a third pulley at the central region 65 of the canopy assembly 12. The line 60 extends downwardly from the third pulley through the central shaft 69 of the canopy, terminating in a knoblike handle 70 (FIG. 3). A plurality of stretchers 74 extend upwardly from the runner 72 to engage the umbrella ribs 16 in the conventional manner.

[0029] The line 60 is a flexible tension member made of any suitable material having sufficient flexibility and tensile strength for the purpose. For example, the line may be a wire cable or a cord woven of any suitable synthetic material. The winder hub is connected to a crank 78 extending outside the housing 37, for winding or unwinding the line. The winder may include a mechanical lock equipped with a release control mounted on the collar 43, operative to preventing winding or unwinding the line unless the lock is disengaged. Details of such locks and winding hubs are known to those skilled in the art.

[0030] With particular reference now to FIGS. 3 and 4, the hub 55 defines the center of the canopy assembly. The ribs 16 extend radially outward from the hub 55 and are pivotably attached so as to raise and lower with respect to the hub. The hub 55 has a central axis (coaxial with central shaft 69 of the canopy), and each rib is pivotably mounted to the hub 55 for pivoting motion substantially in a plane that extends through that central axis.

[0031] Each rib 16 is comprised of an inner rib section 16 a and an outer rib section 16 b of approximately equal length arranged in nearly abutting, end-to-end relation. Each pair of inner and outer rib sections 16 a, 16 b is connected by a rib hinge 80 which connects the rib sections together in pivotable relation, as will be more fully described below.

[0032] The structure of the rib sections 16 a, 16 b and rib hinges 80 is shown in more detail in FIGS. 5-10. FIG. 5 shows a rib hinge housing 81, a generally rectangular tubular component having side walls 82, a bottom wall 84, and a partial top wall 86. The forward and rearward ends 88, 90 of the rib hinge housing 81 are open, as is the major portion of the top 92 of the housing beginning at the forward end 88. The dimensions of the rib hinge housing 81 are such that an end of a rib section 16 a, 16 b can be received closely therewithin.

[0033]FIGS. 6-10 show the manner in which the rib sections 16 a, 16 b are assembled onto the rib hinge housing 81. First, as shown in FIG. 6, an end of an outer rib section 16 b is introduced into the rearward end 90 of the rib hinge housing 81 and beneath the partial top wall 86. The outer rib section is then welded in place. Next, as shown in FIG. 7, the rearward end of an inner rib section 16 a is introduced into the forward end 88 of the rib hinge housing 81 and advanced to a location slightly spaced apart from the forward end of the outer rib section 16 b, as depicted in FIG. 8. Then, as shown in FIG. 9, a hole 94 is drilled through the side walls 82 and through the rearward end of the inner rib section 16 a. Finally, as shown in FIG. 10, a hinge pin 96 is inserted through the hole 94 in the side walls 82 and the rearward end of the inner rib section 16 a to pivotably mount the inner rib section to the rib hinge housing 81. The hinge pin 96 is secured with a nut, cotter pin, or other suitable means for maintaining the hinge pin within the hole 94.

[0034] Operation of the hinged ribs 16 to relieve pressure and avoid breakage of the ribs in the event of high winds will now be explained with reference to FIGS. 11 and 12. FIG. 11 shows a rib 16 in its normal position. Each inner rib section 16 a is supported from the upper hub 55 (FIGS. 3 and 4). Each outer rib section 16 b is pivotably supported from the lower end of a corresponding inner rib section 16 a by way of a rib hinge 80. The rib hinge 80 is permanently affixed to the outer rib section 16 b such as by welding, and the rib hinge is pivotably attached to the outer end of the inner rib section 16 a by way of the hinge pin 96. The bottom wall 84 of the housing 81 extends beyond and parallel to the lower edge 98 b of the outer rib section 16 b and is positioned to confront the lower edge 98 a of the inner rib section 16 a to prevent further rotation of the outer rib section 16 b in the clockwise direction as seen in FIG. 11, thereby maintaining the outer rib section in longitudinal alignment with the inner rib section 16 a. With the ribs 16 mounted to the hub 55, each outer rib section 16 b is mounted to its associated inner rib section 16 a for pivoting movement substantially in a plane that extends through the central axis of the hub (coaxial with the central shaft 69 of the canopy, as previously explained).

[0035] When wind pressure underneath the canopy 12 builds up to a predetermined level, the force, indicated by the arrow 100, will overcome the weight of the canopy and the outer rib section 16 b and cause the outer rib section to pivot upward, as shown in FIG. 12. The housing 81 rotates counterclockwise on the pivot pin 96, as seen in FIG. 12. The lower end of the inner rib section 16 a clears through the top 92 of the housing 81 of the rib hinge 80. This pivoting action removes the tension from the canopy 12 and allows trapped air beneath the canopy to escape, relieving the pressure.

[0036] Once the winds pass, the user can return the umbrella to its normal operating condition by simply pulling each outer rib section 16 b downward against the tension of the canopy 12 until it has returned to its normal position. When the bottom wall 84 of the housing 81 rotates into confrontation with the bottom edge 98 a of the inner rib section 16 a, further rotation of the outer rib section 16 b is prevented. In this position the outer rib section 16 b is in longitudinal alignment with its corresponding inner rib section 16 a.

[0037]FIGS. 13 and 14 illustrate an alternate embodiment of a rib hinge 180 comprising the identical components hereinabove described but arranged in a different manner. The rib hinge housing 81 is reversed, with the end of the inner rib section 16 a being inserted into the rearward end 90 of the housing and welded in place. The adjacent end of the outer rib section 16 b is introduced into the forward end 88 of the housing 81 and held in place by the pivot pin 96. When the force 100 exerted by the wind is sufficient to overcome the weight of the canopy and the outer rib section 16 b, the outer rib section pivots in a counterclockwise direction as viewed in FIG. 14. The housing 81 remains fixed, and the outer rib section 16 b pivots upward through the opening 92 in the housing. When the force has been removed, the outer rib section 16 b can be returned to its original position by rotating it clockwise as seen in FIG. 14 until the lower edge 98 b of the outer rib section confronts the lower wall 84 of the housing 81, in which location the inner and outer rib sections 16 a, 16 b are once again in longitudinal alignment.

[0038] It will be noted that regardless of the orientation of the housing 81, the rib hinges 80, 180 each provide two functions: they hinge the outer rib section 16 b with respect to the inner rib section 16 a, and they provide a stop that longitudinally aligns the outer rib section 16 b with the inner rib section 16 a. It will be appreciated that these two functions are independent, however, and can be carried out by two separate devices without departing from the scope and spirit of the disclosed invention.

[0039] The foregoing embodiments have been disclosed with respect to ribs 16 that are substantially straight in profile, such that the inner and outer rib sections 16 a and 16 b are substantially longitudinally aligned when in their normal positions. However, it will be appreciated that the concept of a hinged, two-piece rib design is by no means limited to a straight rib profile but can easily be adapted to a curved or bent rib profile. Hence whereas the rib sections of a straight rib profile may be said to be substantially longitudinally aligned, the term “predetermined alignment” will be understood to be more general and to encompass not only straight rib profiles but also curved or bent rib profiles that may not technically be considered to be in longitudinal alignment.

[0040] The hinged rib arrangement provides significant advantages. First, the ribs will collapse and not break under wind loads that would bend or break the ribs of conventional umbrellas. Second, the greatest load exerted on conventional umbrella ribs is that of wind loading coming from underneath the umbrella. By eliminating the need for the umbrella ribs to withstand such loads without bending or breaking, the ribs can be made of lower strength material, which is less expensive.

[0041] While the foregoing embodiment has been disclosed with respect to a side-mast umbrella, in which the hub that supports the ribs and canopy is supported offset with respect to the mast, it will be understood that the hinged rib design is equally applicable to a conventional umbrella design in which the hub is supported coaxial with the mast.

[0042] Finally, it will be understood that the preferred embodiment has been disclosed by way of example, and that other modifications may occur to those skilled in the art without departing from the scope and spirit of the appended claims. 

What is claimed is:
 1. An umbrella, comprising: a mast; a hub supported by said mast; a plurality of ribs extending radially outward from said hub; and a canopy supported by said ribs, wherein each of said ribs comprises an inner rib section having an inner end mounted to said hub and an outer end; an outer rib section having an inner end pivotably mounted to said outer end of said inner rib section; and stop means engageable by one of said inner and outer rib sections for limiting pivotable movement of said outer rib section with respect to said inner rib section such that when said stop means is engaged, said inner rib section and said outer rib section are in predetermined alignment; whereby when wind pressure underneath said canopy reaches a predetermined level, said outer rib sections are pivoted upward with respect to said inner rib sections, thereby relieving said wind pressure underneath said canopy.
 2. The umbrella of claim 1, further comprising a housing fixedly mounted to said outer end of said inner rib section, and wherein said inner end of said outer rib section being pivotably mounted to said outer end of said inner rib section comprises said inner end of said outer rib section being pivotably mounted to said housing; and wherein said stop means engageable by one of said inner and outer rib sections for limiting pivotable movement of said outer rib section with respect to said inner rib section comprises a wall of said housing extending beyond and parallel to a bottom wall of said inner rib section and being disposed to be engaged by a bottom wall of said outer rib section when said outer rib section pivots into a position that is in predetermined alignment with said inner rib section.
 3. The umbrella of claim 3, wherein said position in which said outer rib section is in predetermined alignment with said inner rib section is a position in which said outer rib section is substantially longitudinally aligned with said inner rib section.
 4. The umbrella of claim 1, further comprising a housing fixedly mounted to said inner end of said outer rib section, and wherein said inner end of said outer rib section being pivotably mounted to said outer end of said inner rib section comprises said housing being pivotably mounted to said outer end of said inner rib section; and wherein said stop means engageable by one of said inner and outer rib sections for limiting pivotable movement of said outer rib section with respect to said inner rib section comprises a wall of said housing extending beyond and parallel to a bottom wall of said outer rib section and being disposed to be engaged by a bottom wall of said inner rib section when said outer rib section pivots into a position that is in predetermined alignment with said inner rib section.
 5. The umbrella of claim 3, wherein said position in which said outer rib section is in predetermined alignment with said inner rib section is a position in which said outer rib section is substantially longitudinally aligned with said inner rib section. 